Airbed utilizing extruded coils

ABSTRACT

An extruded, seamless and weld-free, loop of flexible material for use as a coil in an airbed. The extruded coil provides more strength and no weak points for coils, and thus a more stable, durable, airbed. In addition, the process of using an extruded coil allows for less manufacturing deviation, and thus a more consistently durable airbed. The extruded coils may be textured inside and out to allow for ease of assembly, and to keep the coils from sticking during inflation and deflation of the product.

TECHNICAL FIELD OF THE INVENTION

The present invention is directed to airbeds, and more specifically toreinforcing structures for airbeds.

BACKGROUND OF THE INVENTION

An airbed is a large rectangular rubber or plastic bag that is filledwith air so that it may be used as a bed. Airbeds are well known in theart and have proven themselves to be very useful. On the one hand, whenthere is no need to sleep on an inflatable airbed, an owner may simplydeflate the airbed (i.e., let all the air out), fold it up, and thenstore it away in a closet or basement. On the other hand, when guestsarrive or when the owner of the airbed takes a trip to a place wherethere is no bed, the owner may simply inflate the airbed and sleep onit.

Most current inflatable airbeds have a single chamber, meaning that aircan travel anywhere inside the airbed since there is no barrier sealingoff one portion of the airbed from another. Therefore, when multiplepeople sleep or sit on the airbed, air is constantly being moved fromone portion of the airbed to another as the weight of the person isshifted.

For example, suppose person A is sleeping on the left side of aninflated queen size airbed. Because there is currently no weight on theright side of the airbed, air would naturally flow toward the unweightedright side of the airbed until an equilibrium pressure condition isestablished (i.e., the right side cannot hold anymore air). Thisshifting of air to the right side consequently would cause the rightside of the airbed to rise.

Next, suppose person B wants to sleep on the now elevated right side ofthe airbed. As person B descends onto the right side of the airbed, thisnew weight causes a redistribution of the air back toward the left sideof the airbed where person A is sleeping. Air flows back to the leftside of the air bed, causing the left side to rise due to the newlyadded air pressure underneath. This unexpected elevation in the leftside of the airbed may even awake person A. Furthermore, each timeperson A or B moves around during their sleep and causes a shift inweight on the airbed, air may also be shifted around inside the entireairbed. This constant movement of air inside the airbed in response toweight shifts causes different portions of the airbed to rise and falluntil the weight movement stops. This constant rocking, elevation ordepression of various portions of the airbed every time one person movescan disrupt a good night's sleep.

To address the unequal distribution of air in an airbed, a variety ofdifferent constructions have been used to control the structure andshape of airbeds. A first type is an internal I-beam structure, having amaterial that extends from an interior of a top wall of an airbed to aninterior of a bottom wall of the airbed. This structure is designed insuch a way to consist of well defined start and stop points, the startand stop points attached to the inner surfaces of the airbed. The I-beamprevents portions of the airbed adjacent to the I-beam from risingbeyond a certain height. However, I-beams are inherently weak because ofthe start and stop points.

An improvement to the I-beam construction is the concept of coildesigns. Coils allow for an effectively closed loop to be attached atupper and lower portions of the loop to the interior portions of theupper and lower walls of the airbed. Because a loop is used, there areeffectively no start and stop points in this design. Thus, thisstructure greatly improves the performance and durability of an airbed.

The most commonly used coils in contemporary airbeds are formed bytaking two flat sheets of material and butt welding the edges of thesematerials together, forming a tube. The butt welded tube is then heatwelded to the top and bottom walls of the airbed with ellipse-likewelds. It has been found that the ellipse-like welds and otherdiscretely shaped welds, such as circular, triangular, orrectangular-shaped welds, provide users with more comfort than a rigid,narrow weld, such as a standard I-beam-type weld. Moreover, theellipse-like welds also allow for optimal strength characteristics inbonding of the coils.

Such a structure is shown in FIG. 1, where an airbed 10 includes coils12 having butt welds 14 at top and bottom edges. Oval welds 16 areutilized to connect the coils 12 to upper and lower walls of the airbed10. The butt welds 14 are contained within and extend perpendicular tothe oval welds 16. The butt welds 14 are not strong enough to maintain apermanent connection of the coil 12, and thus serve as a temporary,end-process weld that holds the coil 12 together until the coil 12 isattached to the upper and lower walls of the airbed 10 by the oval welds16. The oval welds 16 then hold the two ends in place.

One problem with the design shown in FIG. 1 is that the butt weld 14 canbecome a weak spot for the attachment of the coil 12 to the oval weld16. Thus, the butt weld 14 can reduce the durability of the airbed.

SUMMARY OF THE INVENTION

The following presents a simplified summary of some embodiments of theinvention in order to provide a basic understanding of the invention.This summary is not an extensive overview of the invention. It is notintended to identify key/critical elements of the invention or todelineate the scope of the invention. Its sole purpose is to presentsome embodiments of the invention in a simplified form as a prelude tothe more detailed description that is presented later.

In accordance with an embodiment, an extruded, seamless and weld-free,loop of flexible material is provided for use as a coil in an airbed.The extruded coil provides more strength and no weak points for coils,and thus a more stable, durable, airbed. In addition, the process ofusing an extruded coil allows for less manufacturing deviation, and thusa more consistently durable airbed.

In accordance with an embodiment, the extruded coils may be texturedinside and out to allow for ease of assembly, and to keep the coils fromsticking during inflation and deflation of the product.

Other features of the invention will become apparent from the followingdetailed description when taken in conjunction with the drawings, inwhich:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a side perspective view of a prior art airbed;

FIG. 2 shows a side perspective view of an airbed incorporating coils inaccordance with an embodiment of the present invention;

FIG. 3 is a cross-sectional view taken along the section lines 3-3 ofFIG. 2; and

FIG. 4 is a diagrammatic view representing a method by which an extrudedcoil may be produced in accordance with an embodiment.

DETAILED DESCRIPTION

In the following description, various embodiments of the presentinvention will be described. For purposes of explanation, specificconfigurations and details are set forth in order to provide a thoroughunderstanding of the embodiments. However, it will also be apparent toone skilled in the art that the present invention may be practicedwithout the specific details. Furthermore, well-known features may beomitted or simplified in order not to obscure the embodiment beingdescribed.

Referring now to the drawings, in which like reference numeralsrepresent like parts throughout the several views, FIG. 2 shows a sideperspective view of an airbed 20 incorporating coils 22 in accordancewith an embodiment. Briefly described, the coils 22 are formed of asingle-piece, seamless, weld-free, extruded flexible tube of material.

The coils 22 are attached to upper and lower walls 24, 26, of the airbed20 by oval welds 28. Although oval welds 28 are shown in the drawings,other welds may be used, including any type of ellipse-like weld, suchas circular, triangular, or rectangular shaped welds, or more narrowwelds. In addition, although a single weld is shown for attaching a coil22 to the upper wall 24 and another, single oval weld 28 is shown asattaching the lower wall 26 to the coil 22, two or more welds may beused at the attachment of the coils 22 to the upper and/or lower walls24, 26.

In the embodiment shown, the coils 22 are provided as short segments,and a series of coils 22 are provided along the length of the airbed 20.However, in an alternate embodiment, longer coils 22 may be provided,having multiple oval welds 28 or similar welds for attaching theelongate coils 22 to the upper and lower walls 24, 26. In an alternateembodiment, the coils 22 may extend almost the length of the airbed 20,and may be attached by multiple oval welds 28 or similar welds along thelength of the coils 22.

The coils 22 may be cut to proper length, or may be provided by asupplier at a desired length. The coils 22 are then welded in a mannerknown in the art to the upper and lower walls 24, 26. When in place, thecoils 22 provide structure for the airbed 20, as can be seen in FIG. 3.The coils 22 prevent movement of the upper and lower walls 24, 26 in thearea adjacent to the coils 22.

In accordance with an embodiment, the coils 22 are made ofpolyvinylchloride (PVC). However, any suitable material may be used.PVC, however, is typically the material used for airbeds, such as theairbed 20, and thus provides quick and easy welding to the upper andlower walls 24, 26.

The method for making extruded polyvinylchloride flexible tubes isknown, but a process is shown in FIG. 4 for the benefit of the reader.An extrusion mold 30 is utilized for forming an elongate, flexibleextrusion 32. The extrusion mold 30 includes an outer dye 34 and aninner dye 36. The elongate extrusion 32 is extruded from between theouter dye 34 and the inner dye 36.

During the extrusion process, it is important to keep the sides of theelongate extrusion 32 from touching one another so that they will notweld together before cooling. To this end, an internal coolingairstream, indicated by the arrows 38 may be provided for the coolingand separation of the elongate extrusion 32. In addition to or inreplacement of the internal cooling airstream 38, a vacuum, such as viavacuum boxes 40 may be supplied on the outside of the elongate extrusion32, for pulling the walls of the elongate extrusion 32 apart. Theinternal cooling airstream 38 and/or the vacuum boxes 40 may extend anappropriate length beyond the extrusion molds 30 so that the elongateextrusion 32 is cooled when it is no longer supported by the internalcooling airstream 38 and/or the vacuum boxes 40.

The coils 22 of the present invention provide a stable structure for anairbed, such as the airbed 20. The coils 22, because they are formed ofan extruded material, do not include butt welds or any other potentiallyweak locations.

If desired, the coils 22 may be textured on the inside and outside toallow for ease of assembly. Texturing would also prevent the coils 22from sticking during the inflation and deflation of the airbed 20.

The use of the extruded coils 22 permits coils to be produced with lessmanufacturing deviation. As such, the size of the coils 22 is moreconsistent, providing a more consistently durable airbed 20.

Other variations are within the spirit of the present invention. Thus,while the invention is susceptible to various modifications andalternative constructions, a certain illustrated embodiment thereof isshown in the drawings and has been described above in detail. It shouldbe understood, however, that there is no intention to limit theinvention to the specific form or forms disclosed, but on the contrary,the intention is to cover all modifications, alternative constructions,and equivalents falling within the spirit and scope of the invention, asdefined in the appended claims.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. The term “connected” is to beconstrued as partly or wholly contained within, attached to, or joinedtogether, even if there is something intervening. Recitation of rangesof values herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate embodiments of the invention and does not pose a limitationon the scope of the invention unless otherwise claimed. No language inthe specification should be construed as indicating any non-claimedelement as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

1. An airbed, comprising: an upper wall; a lower wall; and at least one coil connected between the upper wall and the lower wall, said at Least one coil comprising an extruded, weld-free, loop of flexible material.
 2. The airbed of claim 1, wherein the coil is seamless.
 3. The airbed of claim 1, wherein the coil is connected to the upper and lower walls by ellipse-like welds.
 4. The airbed of claim 1, said at least one coil comprises texture inside and out.
 5. The airbed of claim 4, wherein said at least one coil comprises polyvinylchloride.
 6. The airbed of claim 1, wherein said at least one coil comprises polyvinylchloride.
 7. A method of forming an airbed, comprising: extruding at least tone coil, said at least one coil comprising a weld-free, loop of flexible material; and connecting said at least one coil to an upper wall and a lower wall of the airbed.
 8. The method of claim 7, wherein connecting comprises welding said at least one coil to he upper and lower walls.
 9. The method of claim 7, wherein connecting comprises welding said at least one coil to the upper and lower walls using ellipse-like welds.
 10. The method of claim 7, wherein said at least one coil is seamless.
 11. A method of forming an airbed, comprising: obtaining at least one coil, said at least one coil comprising an extruded, weld.-free, loop of flexible material; and connecting said at least one coil to an upper wall and a lower wall of the airbed.
 12. The method of claim 11, wherein connecting comprises welding said at least one coil to the upper and lower walls.
 13. The method of claim 11, wherein connecting comprises welding said at least one coil to the upper and lower walls using ellipse-like welds.
 14. The method of claim 11, wherein said at least one coil is seamless. 